The world of Warhammer is one that is always tettering on the edge of sanity. Looking at their artwork, we always see images that have compelled us to this world, including warriors with scrolls attached to their armour and holding lucky charms of fish and the like.
One thing I've always found is to 'sell' that brand of crazy to non-hardcore players. It's hard to get players to accept the superstition, because we as modern people are not a superstitious bunch. The books are filled with wonderful little superstitions like that.
One thing I really liked about 2nd edition was the idea of trying to get players to buy into those superstitions via items like Incription Scrolls and Lucky Charms that ACTUALLY had a game effect. That was excellent.
So I will be doing a house rule to include things like that.
A poor quality item might add a Fortune and Misforunte dice
A normal 'charm' would add a Fortune dice
A superior charm would add two Fortune dice.
All of these things would be 'attuned' to a god, so a charm of sigmar would help in combat, whereas a charm of Shallya would only help in preventing combat or healing. Each item is a 'one-shot' use so you would have to purchase more.